I want to customize zen cart so that each user must be registered in order to shop from the store. When he registers he will have the option of entering another (already registered) user as his referral. This can be done up to a certain amount of levels. For any purchase made his referral tree will be credited a certain (and different based upon depth) amount of money. An admin panel should be created, so that the admin can check if there are pending amounts for all users, and clear these amount upon payment. This payment does not have to be implemented in any way. Just the modification of users pending amounts.
It is a kind of network marketing addition but in its VERY very simple form (at least in the beginning).
The project would require some documentation on the changes made (not extensive)